Teach people how to play
Every time there is an event where people play in fortress, it really shows how many people don't know what they are doing. Attacking enemies they aren't proficient against even though there are enemies they are better agains. People not using any hex or charms, aurors using bat-bogey on a foe before attacking it.. The list is long and it kinda stops the natural evolution this game could have. Higher fortress chambers, more difficult fights and stuff like that is kinda impossible for these players(and people who plays with them).
A solution could be if players gaining the ability to use hex/charms in adversary fights.
The fights could be harder to compensate but there could be a tutorial/ingame tips where the game suggest to maybe shield yourself, use hex's and charms.
A more simple solution could be to have tips when the game loads that aren't "Remember to be alert at all times.."
Or just above it if you are afraid of getting sued